What is the recommended tire air pressure for the E46 BMW 330 ZHP?

[quikryptonite]

I have been to tirerack.com and can't find what the recommended air pressure is for the tires on a 330i with the performance package. What do you guys/gals suggest?

[Crickett]

The BMW-recommended pressures are listed in two places: driver-side door placard & in the manual. I'll make it three places:

• 225/40ZR18 - 32 psi (39 psi for max weight)
• 255/35ZR18 - 38 psi (46 psi for max weight)

[quikryptonite]

Thanks, I will be picking up mine this weekend and want to make sure I am driving 1300 miles on the correct tire pressure. Thanks again.

[gr330zhp]

The BMW-recommended pressures are listed in two places: driver-side door placard & in the manual. I'll make it three places:

• 225/40ZR18 - 32 psi
• 255/35ZR18 - 38 psi

This.

Though 2 BMW dealers told me 32psi all around was "fine"

[Marcus-SanDiego]

Quik, congrats on getting the 330 ZHP.

[Crickett]

Thanks, I will be picking up mine this weekend and want to make sure I am driving 1300 miles on the correct tire pressure. Thanks again.
Not a problem. Congrats (in advance) for picking up a great car!

[jvr826]

Personally, I think 32 is too low, and running more in the rear with a staggered setup means even more understeer than the car already has built-in, way, way too much.

UUC has a good tuning guide on their site which is impossible to find, but here's a direct link. It shows how different changes, including tire pressure, effect handling characteristics...

Setup of the Sway Barbarian (http://www.uucmotorwerks.com/html_product/sway_barbarian/html_sway_bar/setup.htm)

[Crickett]

Personally, I think 32 is too low, and running more in the rear with a staggered setup means even more understeer than the car already has built-in, way, way too much.

UUC has a good tuning guide on their site which is impossible to find, but here's a direct link. It shows how different changes, including tire pressure, effect handling characteristics...

Setup of the Sway Barbarian (http://www.uucmotorwerks.com/html_product/sway_barbarian/html_sway_bar/setup.htm)
That link is great info for the novice tuner / autoX'r! I never could remember that stuff on a track day . . .

Also, keep in mind 32/38 is BMW's every day / average-use recommended pressure; pressures for the track / autoX course is another matter entirely.

[az3579]

The BMW-recommended pressures are listed in two places: driver-side door placard & in the manual. I'll make it three places:

• 225/40ZR18 - 32 psi (39 psi for max weight)
• 255/35ZR18 - 38 psi (46 psi for max weight)

The door jamb doesn't say if that weight is for max load, it just says that those are the pressures when cold. I run these pressures all the time. Where did you see it say that's the "max weight" pressure?

[Mtnman]

I run 36.5 front and 39.5 rear at driving temps. Never had uneven tire wear from it at all. and i run 235/255, but also ran 235/265 on same pressures.

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[billschusteriv]

All good information here.

I'd also recommend checking the sidewall of your tires just to confirm they are rated to handle the pressure - they should be but it doesn't hurt to check.

I have a different tire/wheel size and setup so this is apples and oranges - but FWIW, I was running a lower pressure (6-8lbs low) in my Hankook V4s on factory 16s and I had awful handling issues in the rain. I talked with Dane and straightened myself out. Increasing the pressure closer to factory specs made all the difference in the world.

Have a safe drive! Congrats on the purchase! Take some pics on the road trip!

[danewilson77]

I swear I'm running 42/48......front/rear.

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[Mtnman]

Riding on rocks! Do you see any abnormal center tire wear?

[danewilson77]

Nope. All is well. I think mine are too high. I may be thinking wrong. I will check tomorrow.

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[Johnmadd]

The door jamb doesn't say if that weight is for max load, it just says that those are the pressures when cold. I run these pressures all the time. Where did you see it say that's the "max weight" pressure?http://i1210.photobucket.com/albums/cc407/johnmadd1979/2011-03-09_22-29-55_159.jpg

[jvr826]

What you choose depends on the characteristics of your specific tires. The settings on the strike-plate sticker are recommended for the factory supplied tires and are just guidelines... a good starting point though.

I've run several different street tires on my car over the years: Original PS1, PS2, BFG KDW2, Nitto Invo, Dunlop Star Spec, and now Bridgestone RE-11's. I've had to vary the pressures used by a few pounds either way to get the handling I like. There's no single setting that worked for all of those different tires.

For instance, the RE11 has a softer sidewall than the Star Spec, so in order for me to get the crisp turn-in I like, 40psi is where they respond the best... but I find mid-corner grip is compromised with that much pressure, so I sacrifice turn-in for mid-corner grip and lower to about 37psi hot.

The Star Specs were blissfully happy at 36-38psi hot. They have it all... crisp turn-in due to their stiffer sidewall, outstanding stick mid-corner and beyond. I will get another set when these RE11s are used up. The RE11 is a great street tire, but for autocross and pushing it... the Star Spec excels for me!

[Johnmadd]

My tires say max 51, anybody ever ride maxed out?

[Rovert]

My tire pressures were at the high end of 40 when I was on the highway in LA and the temps were around 100 outside. I can't remember my tire temps but they were running borderline in the "be cautious" zone. The ride was fine.

[billschusteriv]

From Tire Rack: (http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=1)

Advantages of Correct Tire Inflation

Maintaining correct tire inflation pressure helps optimize tire performance and fuel economy. Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles. Tire deflection (the tread and sidewall flexing where the tread comes into contact with the road) will remain as originally designed and excessive sidewall flexing and tread squirm will be avoided. Heat buildup will be managed and rolling resistance will be appropriate. Proper tire inflation pressure also stabilizes the tire's structure, blending the tire's responsiveness, traction and handling.

Disadvantages of Underinflation

An underinflated tire can't maintain its shape and becomes flatter than intended while in contact with the road. If a vehicle’s tires are underinflated by only 6 psi it could lead to tire failure. Additionally, the tire’s tread life could be reduced by as much as 25%. Lower inflation pressure will allow the tire to deflect (bend) more as it rolls. This will build up internal heat, increase rolling resistance and cause a reduction in fuel economy of up to 5%. You would experience a significant loss of steering precision and cornering stability. While 6 psi doesn’t seem excessively low, remember, it usually represents about 20% of the tire’s recommended pressure.

Disadvantages of Overinflation

An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle's tires are overinflated by 6 psi, they could be damaged more easily when running over potholes or debris in the road. Higher inflated tires cannot isolate road irregularities well, causing them to ride harsher. However, higher inflation pressures usually provide an improvement in steering response and cornering stability up to a point. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures. The pressure must be checked with a quality air gauge as the inflation pressure cannot be accurately estimated through visual inspection.

[norman@southbayBMW]

You can try 36 psi on all four tires

[danewilson77]

I am runnin 32/38 F/R now...

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[Mike V]

I run 33 all around in most of my cars. As others have mentioned, the recommended pressure induces understeer. It helps keep the average American driver out of trouble since understeer is easier to control than oversteer if you have no idea what you're doing (which most don't since our driver training sucks). Same reason BMW went with with a staggered setup on the 96 M3 since so many people were crashing their 95s.

46 is insanely high though. When I first bought the zhp, I was at a tire shop and the tech looked at me weird and explained that he has to air up to what the sticker says for liability reasons. I told him ok, I left the shop... and as soon as I could, I pulled over, looked at the sticker in shock and drained 13 psi from the rear tires. :)

[danewilson77]

After I got them mounted and balanced they were 48 front and rear...lol. I could tell....

[adb1028]

I ran on 32 all around last year when I got the car.....decided to go 34, 38 this year and my mpg's went from 22.3 to 23.9. Better feel too!

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[nk_zhp]

33 - 35 all around. Low PSI upfront makes the wheels more prone to bents. BMW's recommended setting gives way too much under-steer for my liking.

[balticvid]

The tire pressures on the door plate were written buy lawyers. They want higher pressures
for liability reasons.
Inside your drivers manual is where you will find the proper tire pressures.

[danewilson77]

The tire pressures on the door plate were written buy lawyers. They want higher pressures
for liability reasons.
Inside your drivers manual is where you will find the proper tire pressures.

For comparison sake.

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/1-31.jpg

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/ZHPTirePressure.jpg

[nike001]

I think I run 33/38 or something like that.

I'm having trouble finding a good pressure to run at for my 17 winters though. IIRC, i ran 33-34 PSI in them and I have center tire wear :/

[jsfbmw]

I'm having trouble finding a good pressure to run at for my 17 winters though. IIRC, i ran 33-34 PSI in them and I have center tire wear :/
Seems unusual for this wear to be due to those tire pressures. For winter I have 17" wheels with 205/50 tires and run 34 all around. Wear has been fine. Agree that for summer tires the 32/38 setting creates too much understeer. Prefer 36/38.

[nike001]

Seems unusual for this wear to be due to those tire pressures. For winter I have 17" wheels with 205/50 tires and run 34 all around. Wear has been fine. Agree that for summer tires the 32/38 setting creates too much understeer. Prefer 36/38.

I had middle wear, but I just assumed it was because fun in the snow (DSC off :)) so I just went with it.

But the other day while cleaning the garage and moving the tires, it seemed the tires made sort of a U shape while rolling across my garage floor

[zhpnsnv]

Why does my sticker say only 39 and 46?

[BavarianZHP]

Why does my sticker say only 39 and 46?

You're only reading the first line. That's the maximum value (car fully weighted with 5 passengers and cargo).

EDIT: Sorry everyone for reviving an old thread - I happened to click on a link from another thread and then responded to this one forgetting I was here :P

[dpark]

As the original owner of my E46 ZHP, I found that running the factory recommended tire pressures cause SERIOUS premature wear on the rears (balded in the center of the tire) and as a result my factory tires were shot by 10,000 miles. Since then, I have run the front and rears at 31 PSI. No question the car understeers a bit but all four tires have even tread wear.

[az3579]

In case anyone reads over the thread and wonders why anyone would set pressures to 39/46, that was what the sticker says on some ZHPs. It shows no other tire pressures on the sticker and makes no mention that those are for a fully loaded car only.

Seems to me that BMW made a very poor choice putting this sticker on some ZHPs.

http://uploads.tapatalk-cdn.com/20161130/cea33f08eed9a53c7a0f84dd25f66189.jpg


Needless to say, I haven't run those pressures in years considering a tires max pressure is in the low 50's typically and a track day can easily push them up to 50's.

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[Eugene]

Sorry to bump up old thread - but I have the same sticker in my ZHP as above - with only the max pressure. I also read in the Facebook group that the coupes have 32/38 recommended PSI....should I be running 32/38 PSI on my daily driven ZHP sedan? Most of the time it's just me and the wife in the car

[san]

Sorry to bump up old thread - but I have the same sticker in my ZHP as above - with only the max pressure. I also read in the Facebook group that the coupes have 32/38 recommended PSI....what PSI should I be running on my daily driven ZHP sedan?

I have a coupe and ran 32/38 on stock wheels and I got about 38k miles on conti dws06 tires when I was living in IN. The rears were done but the fronts were about half worn. Now I run 245/40 R17 and set them to 34 all round because of shitty MI roads. I got about 40k miles before they were worn to the cords.

I know you asked for a sedan but I’m throwing my experience out there for reference. I would start off near the recommended pressures and change if needed based on tire wear and how the car rides. What works for someone else might not work for you because most of our cars don’t have the same wheels, tires, suspension, mileage, bushings, roads and also weather (ambient temperature) also plays an effect...


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